Flow stabilizing device for gun-type oil burners



March 24, 1953 D. L. GETZ ETAL FLOW STABILIZING DEVICE FOR GUN-TYPE OIL BURNERS Filed Jan. 16, 1948 3 Sheets-Sheet l March 24, 1953 1,, 5512 EM 2,632,499

FLOW STABILIZING DEVICE FOR GUN-TYPE on. BURNERS Filed Jan. 16, 1948 3 Shgets-Sheet 2 March 24, 1953 D. L. GETZ ETAL 2,632,499

FLOW STAEILIZING DEVICE FOR GUN-TYPE OIL BURNERS Fi Ied Jain. 16, 1948 s Sheets-Sheet 3 35 45 88 ez a 1151 99 I "9 I 3 I75 79 2 [I o 63 j Y 54 l (Ittomegs Patented Mar. 24, 1953 por'ation 6f 'oliio :App licationrJanuary 16, 1918, Serial No. 2','713

(c1. ris-sac) This invention-relates to oifburners for. heatin apurposes and thel-like, I

gm .of the principal objects of the I-invention iiS I to r-provide an oil 1' burner for Sn'eating purposes which is of :-improved, simple and reliable con- -::-St11l.l0ti0l1, which does notrequire frequent servicing or adjustment, and which will assure-steady, iuniformrquietand efiicientcombustion.

-A Anotherzobject is-to provide an oil burner 11 which :the liquid fuel .is supplied at a metered srateto 'anlatomizing'jpump and mixed with air 1, oradelivervto a -flow stabilizing device in which the ifuelis separated from theair and then del livered to the' nozzle ina steady and constant .iflO'W under balanced pressure conditions uneffected :pulsations in thesupply pressure for :sremixing :with thesair and combustion.

@An additionalobjecteis toiprovide an oil burner ,ihavingwa i-flow stabilizing device which is adapted to l separate the latomize'd mixture of liquid fuel rand air for separate :delivery to the nozzle and which includes a chamber for entrappi-ng air to userve asafieushion for dampingioutpulsations in the -fuel supply pressure and facilitating delivery oira-steadyand constant flowxof liquid fuel-to the nozzle.

:11; is also an object f the invention to provide a; fiowstabilizing device for an --oil burner which ;includes :a differential diaphragm responsive to rtlie weight-0f the liquid fuel eifective thereon to viregulategthe :rate of supply ofvfuel "toithe nozzle nandwhieh also includes :a valve zcont-rolled :by the rdiaphragm and constructed for selfaligningi'operationsgtherewitli and with its valve orifice to vzirnin'imize f'fricti'on and resulting:err'atic operation.

--"=elevationwith-a ortion of the 'cor'nbus'ti'onmea'd broken away to illustrate details-of internal-eon- *"struetionfandarrangement; v

.Fig. its a view "partly in rear elevation and ;partly in vertical section on the line"4-4 of Fig. 3

igit a view in ivertl'c'al section on" the line of 'Fi'gffz "andals'o of Fig. 4';

Fig. 6 "is an "enlarged detail view fof the nozzle, the view being in section substantially Oh the lihe ,66 of IFigCT; H

Fig. 7 is "a' detail viewnf "thenozzlefon a still larger scale taken in "sectionsubstantially on *the line '1--1 of Fig.6;and

Fig. 8 is an enlargedfragmentary view difthe metering valve and 'difierentiardiaphragm -'o'fti'lhe Referring to the drawings, which illustratez a preferred embodiment "of the invention, Fig. illustrates. schematically the "operative relation of themainpomponent parts "of the oilfburn'e'r ant the paths of 'fiow of fuel "therethroughtlie "on being represented by short "jdash lines,"tlie "air by long dash lines, and the mixed oil "and air by alternating short i'an'd long dash flines Toll :met'eringpump swan atomizingairpunipij anti "a fan "or ilolower '32 for supplying 'seconda'ryifaiijr are all driveirby a'n 'eleetric 'indtor "3'3 tnrdugh shaft 34 having a flexible conneotion35 to the drive shaft 36 of the motor. iAdainperfiil *ineluding an adjustable slotted sleeve menirer ta controls the supply of'air'to the'blower32.

js'tr'ainer ll and a tapered shutoff "vane 4! "carried bythe'rod' l'3 of a piston? aJ-pressurechainber as in the top of the metering gpump. A :sprin dfi'horm'ally b'ia'se'spiston T4 to a IJ'OSItlGncIGSih'g valve 42. A pressure connection"?! provided from the atomizin g air pump '31 to the ressure started, the pressure from pump T31 acts toniove (the piston against spring .46Jto apositio'n opening valve 12 to admitoil to the meteringpu'mp. The low pressure side of piston. is vented to the suction side ofjthepump "3| as indicated at T8.

The metering-pump 30 supplies oil at a metered rate totheatornizing pump 3l, which-mixes-this oil with air and suppliestheresulting atomized mixture toa flow stabilizing device indicatedlgenerall'y a'ttil and. described in detail hereinafter in connection with Figs 5v and 8. Theifiow stabilizer 50 includes-a chamber 5] in which theiatomized mixtureis allowed to separate intoair and liquid oil. The air is transmitted througha tube -52 to the nozzle in the "combustion ahead -5ito+serve as primary air. A differential diaphragm indicated generally at "56 controls the isup'ply of oil fro'm the flow stabilizer: 50 to the nozzle, the oil be'ing transmitted to the nozzle thr'ou'gh a tulle -*5'='| amounted within the a'ir tub'e '52. At the; nozzle,

the liqui'd oil and primary air are mixed aha igni-tedhy a spark induced between the "eleetrodes 513, and the secondary air issupplied thereto from pump 30 is in turn bolted to the pump 3|.

outer side of casing I5. :with a fitting 81 for connection to the oil line from the supply'tank, and it is also formed with the blower 32 as described in detail hereinafter in connection with Figs. 5 to 7.

The general construction of the burner is illus trated in more detail in Figs. 2 to 5. As shown, it includes a main supporting frame or casting forming a casing 60 having an adjustable base BI. The motor 33 is mounted at one side of the casing 60 and is connected through the cable 62 with a high voltage transformer 03 which is also mounted on the side of casing 60. The casing 60 forms a housing for the fan or blower '32 and is provided on its side opposite the motor with an inwardly extending flange 65 forming an air intake passage for the blower from the damper 31, which is bolted to casing 66 adjacent this flange 65 as shown in Fig. 4. The atomizing air pump 3| is supported on the main frame by being bolted to the damper 3i, and the oil metering A removable cap 66 on the side of casing 60 provides ready access to the terminals of transformer 63 for connecting the lead cables 61 to .the electrodes 58 at the nozzle.

The construction and operation of the oil metering pump 30 are shown in detail in our copending application Serial No. 188,450, filed October 4, 1950, as a continuation-in-part of the present application. As shown, the pump includes a casing I5 defining a main chamber I? which initially receives the oil from tank 40 admitted by valve 42, the lower end of this chamber being closed by a cover plate '50 provided with a drain plug I9. The upper part of casing I5 is formed to' define the pressure chamber 45 for piston 44, and the pump casing is also formed with an intake chamber 85 for receiving oil transmitted by strainer 4|, which is mounted adjacent chamber 85 in a cover 83 bolted to the Cover 83 is provided a boss 88 for receiving the outer end of drive shaft 34 as shown in Fig. 4. The oil entering chamber 85 is transmitted to chamber 'I'I through theipassage 90 controlled by the tapered valve 42 as'alrea'dy described in connection with Fig. 1. An adjustable air vent 95 for chamber TI 'is provided in the top of easing I5 as shown -'in Figs. 2 and 3.

The pump casing I5 is formed in its lower part to define a pair of coaxial cylinders 99 each having a piston I mounted for reciprocating and oscillating movement therein. Each cylinder is provided with an intake port IOI from chamber 11 and an outlet port I02 spaced angularly from port IOI and leading to a passage I03 in casing "I having a discharge port leading to the atomizing air pump SI. A plug I05 serves as a re- Each piston I00 has a pair of grooves I02 so that only one groove and port can be in registry at one time.

The reciprocating movement of the pistons in .cylinders 09 is produced by an eccentric crank pin 1 I0 at the lower end of a crank III mounted within chamber I1 and driven through a worm gear ll4formed integrally therewith and meshing with a worm portion II5 of shaft 34. Crank pin IIO engages the inner ends of pistons I00,

and a rocker I20 cooperates with shaft III to provide for oscillating movement of the pistons at each end of the strokes thereof suflicient to cause the grooves I06 to register with orts IOI during the suction strokes of the pistons and to cause grooves I01 to register with ports I02 during the pressure strokes of th pistons.

This oscillating movement of the rocker I 20 and pistons I00 is effected in timed relation with the reciprocating movement of the pistons by means of upwardly projecting cam lobes I26 arranged at diagonally opposite positions on the sides of rocker I20 in cooperation with an integral cam portion I30 of crank III. This cam I30 is arranged in such angular relation with the crank pin I I0 and the axis of crank III that its leading edge will contact and begin to depress one cam lobe I26 just as its trailing edge clears the other cam lobe I26, this point in the revolution of crank III representing the end or the suction stroke for one piston and the end of the pressure stroke for the other piston. In addition, the total angular extent of cam I30 is such in relation to the cam lobes I26 that rocker I20 is held in substantially fixed position during the full stroke of each piston and is then rocked with the pistons as the crank pin I I0 passes over dead center in preparation for the next strokes of the pistons.

The construction and operation of the atomizing air pump 3i are shown in detail in our copending application Serial No. 188,451, filed October 4, 1950, as a continuation-in-part of the present application. The pump housing I40 is formed with a pair of overlapping cylindrical chambers I44 and I42 extending completely therethrough, the chamber I4I being of larger diameter than chamber I42. A cylindrical rotor I45 of smaller diameter than chamber I4I is mounted therein for rotation with shaft 34 eccentrically of chamber MI. The rotor I45 is partially hollowed at I46 for purposes of balance, and it is provided with a suitable oil seal I4! adjacent gasket I44 as shown in Fig. 4.

The oil from the metering pump 30 enters the chamber I4I through a port indicated diagrammatically at I53 (Fig. 1) which opens into chamber I4I adjacent chamber I42. The air for mixing with the oil in chamber I44 enters the pump initially through a port I55 (Fig. 2) in the outer surface of housing I40 and flows to chamber I4I through a sinuous groove forming an air mufiler and indicated diagrammatically at I5'I in Fig. l. A discharge or outlet passage I i provided in pump housing I40 on the opposite side of inlet I53, the outlet passage I60 opening into chamber I42 and communicating therethrough to chamber I4I. A fitting IBI is mounted at the outer end of outlet I60 to provide a connection to a pipe or hose I32 (Figs. 2 and 3) leading to the flow stabilizer 50 as described in connection With Fig. 1.

A valve H5 is mounted for rocking movement in chamber I42 to control communication between inlet I53 and outlet I60 as the rotor I45 revolves. This valve I15 is mounted on a pin or dowel ITI positioned concentric with chamber I42 and set in pump housing I5 and air damper 37 as shown in Fig. 4. A spring I90 provides a constant biasing force urging the valve I into continuous contact with the rotor I45 as the latter revolves in chamber I4 I It will accordingly be seen that the valve I15 is at all times effective to prevent communication betweenthe inlet passage I53 and the outlet passage I60 through the chamber I42 or the lower'part of the chamber I 4|. The only communication from inlet I53 to outlet I50 is thus through chamber MI in the direction of rotation sa a-ree oftherotor- M5. During themajor part or each revolution; the rotoracts to separate chamber UH into two portions which constantly vary insizeand constitute a suction portion connected with the inlet passage I53anda pressure portion connected with the outlet I00. The relative sizesoithetwo chambers and rotor I45 are such as to provide a total capacity for the chamberswhich is in excess of'the eiiective capacity of the cylinders 39- in the oil pump 30, and since it does not fill this space, a quantity of airis also taken in suiilcient to make up the deficiency. The resulting mixture of -oil and air is'thenforc'ed out through the discharge passage B60.

The atomized mixture of oil and air from pump 31 is transmitted through the pipe or" hose I62 to the fiow stabilizing device 50, which:includes a housing 200 (Fig. boltedwithi-n casing 60 and defining therewiththe' chamber'5l. A casting '2 01- is mounted incha'mber 5! for slidingmovemen-t on two pins 202 set in the wall of housing 200, and a spring 203 is positioned to exert tension between casting 2M and thead jacent wall of casing- 60 to urge casting 20! in V the dire'ctionof the combustion head. The tube 52 is -fixed in the end wall of housing 200 in open communication withthe chamber 5L and the tube 5'! extends through tube 52 andis secured to casting 20I for movement therewith with re-' spect totube 5-2, and housing 200.

, asto-givethe inner compartment 206'asubstantiallly greater area in horizontal section than outer compartment 201. The lower end of wall 205 terminates above the bottom wall of housing 2'00 and is closed by the differential diaphragm unit 56, which includes. a flexible member 210 (Fig. 8) of rubber or like suitable materialprovided with reinforcing plates 2| I and 2:12 and. a supporting ring 213 bolted to the bottom edge of; walla205. Abutton 2l5.having a. ground upper surface 2:l0 is secured in: the. center of the aha"- phragmunit as shown in Fig. 8.

Abell-shaped portion 220 of casting 20l forms a. third compartment 22lwithin compartment- 206which: is. closed at its upper end but communicates at itsv lower .end with the compartment 206; Ahollow boss or stem portion 222 ofcasting 201 extends. downwardly within compartment 22 I" to provide a connection through its internal passage 22.3. with apassage 224 in'the'upper part of the :casting 20I leadinginto the tube 51. The lower end of passage 223 includes a countersunk valve seat 225: and a diverging outer mouth portion-226 as best shown in Fig. 8. This passage is, controlled by a valve pin 230 having a tapered upper portion 23 I terminating. in a rounded upper end232 adapted to engage valve seat225. The lower end of valve pin 230hasa ground surface 233 supported on the complementary ground. surface2 16 of button 215.v

Inthe operation of this part of the burner. the atomized mixture entering the flow stabilizer from pump 3| separates in chamber 5|, the liquid oil dropping initially into compartment 201 and oil' overflows wall 5 205 and begins to fill tneinnerr compartment 206;- andat the same time it cntraps air' in the compartment n li As the level of liquid riSesimcompart'rhent Z 05 it exerts a force against the top of?v diaphragm unit 50 counteracting the force of the liquidin the outercompartment, 201'. Since the effective area of compartment -20'6' is greater than 'tnat' or' compartment 201; the: diaphragm Will begin to move downwardlyas soon as the liquidin the compartment-2'06 rises to apoint where its weight" balancesthe weig ht of the liquid abovethe-level of the diaphragm in the outer compartment-201; This movement of the diaphragmallows valve pin 230 to move similarly downward" away from: valve seat 225'; thuspermitting' the liquid 'oil begin to' fibw upwardithrough passage 223 to thee nozzle; The more the level rises within compare-"- ment 205, the more the diaphragm will moi/ate increase the opening past the tapered valvelpor tion: 23l and allow more liquid'fuel to pass tozthe nozzle until abalanced position is reachedat";

. which the amount of liquidfuel entering the chamber 5| and theamountileaving bywayof; passage 223. will bexequa-l;

After a balanced. position of: the valve and dia phragm is reached, the rate atwhichmthe liquidi oil flows through the chamber will remain at'zai I constant rate equal to theioutput'of the oil-.imeter ingi pump'. If there is a change :in1thezoutputi ofthemetering pump, thezresultingl change-in: the: level of liquid in compartment=.206. w'illmproa duce: a corresponding movementof; the; diaephragm' uniti untila balance1isiagainrreached. It should also. be noted that. the: air entrapped. in";

the'compartment221 acts asza cushion to absorb.

pulsations inthe fuel supply line from thexpump: 31, this cushioning action being; augmented; by. the .air at the top of chamber. 5i and also vbyrthe-ifree action of the diaphragm; thus; assuring a steady and constant flow of fuel to the nozzle;

The: construction of". the combustion head is best shown in Figs; 31 to '7; 'Anroutcrsair. tube 250I: is :bolted: to the front. partlcfcasing 60 liby means of: a supporting ring 251' and 3 opens directly into= theinterior'ot casing-60', and an outerair cone 252 is bolted in theouter endiof tubltifl; inner. air cone 2531s mounted within the outer end -of tube 250' and includes inclinedairsjwirl plates or fins 2,54 which are integrally formedwith or otherwise securedto' cone 253 and ext'end outwardly intothe annular passage 2 55 between cone253 and the inner surfaceof tube 250. Gone 2 53 maybe readily-secured in position by 'form ing two'of the plates 254' to receive a mountingscrew for attachment to tube 250, as indicated at 25421. in Fig. 3 The rear'end of cone-253 formed in its lower part with an integral baflle portion 250 partially closing the entrance to-the passage-251 within the cone-'253a nd thus limit? ing the amount 'ofsecondary air released closely adjacent the=outlet of the'nozzle this arrange ment having been found to give combustion of increased efficiencyinoperation; In this con-"- nection, reference is made to our co -pendinga'p plication Serial No. 188,448; filed October 10, 1950; as a-continuation-in part of the present application.

The construction of the nozzle is shown in" de tail in Figs; 6' and '7. It includes an-outeror .l'et' portion 260- and an inner orswirl portion 26 The jet 260 has a; tapered discharge orifice 2B2 ati-ts 'outerend and is mounted on the-front end or when, whichis ixrturn-supported subst'am tially'centrally' of tube 250 by a bracket 263 which also supports the electrode cables 61 and electrodes 58. The nozzle is thus held in substantially centered relation, with the inner air cone 253 as shown in Fig. 5.

The swirl portion 26l of the nozzle is mounted on the front end of tube 51 and has sliding clearance within jet 260 but is normally held with its front end in contact with the front end of the jet by the action of the spring 203 in the flow stabilizer 50. Swirl 251 has a hemispherical button 265 at its front end which is thus normally held within the larger end of the jet orifice 262 to assure proper jet action. A plurality of axially extending grooves 210 are formed along the outer surface of swirl 25l, and similar grooves or slots 21| are cut in the front end of the swirl, each slot 21! connecting with a groove 210 but being angularly arranged as shown in Fig. 7 to give a spiral or swirl effect to fuel passing therethrough. Each groove 210 is also connected with the interior of swirl 26! by a radially arranged passage 212. r

It will thus be seen that liquid fuel from the chamber 256 in the flow stabilizer travels through tube 51 to the swirl 26! and out through the passages 212 into grooves 215. In the meantime, the air from chamber travels through tube 52 under pressure and through the grooves 210, where it picks up the liquid oil and is discharged through orifice 252 withv a swirling efiect imparted by the angular arrangement of slots 21! for combustion with the secondary air. supplied through passages 255 and 251 from the blower 32. At the start ofeach burner operation, a spark is induced between electrodes 58, and the secondary air passing through passage 251 blows the spark into the atomized mixture of air and liquid oil discharged from orifice 262 to effect ignition of the fuel. Thereafter the burner will continue to operate so long as fuel is supplied to the nozzle.

In the operation of this oil burner system as a whole, the liquid oil from tank 40 passes through strainer 41 insufficient volume to fill the chamber 85 in oil pump housing 15, but valve 42 prevents the oil from entering chamber 11 as long as the motor 33 is idle. As soon as the motor is started, it sets the two pumps in operation, and the pressure air from the atomizing pump 3| is supplied as described to the pressure chamber 55 in the oil pump to move piston 44 to a position opening the shutoff valve 42, thus allowing oil to flow into and fill the chamber 11. This oil is then drawn into the cylinders 99 and then pumpedto the atomizing air pump for mixture with air and delivery to the flow stabilizer 55, the oil thus providing continuous lubrication for the air pump 35. y

The atomized mixture of oil and air entering the how stabilizer separates in chamber 5i, with the oil collecting first in compartment 201 and then overflowing into compartment 205 as already described until it reaches a height in the inner compartment 266 sufiicient to cause the diiferential diaphragm to begin opening valve pin 235. When this occurs, the continued weight of the fuel and the pressure of the air in the upper part of chamber 5|, which amounts in operation to approximately 3 pounds gage pressure, forces the oil up through passage 223 and through the tube 51 to the nozzle, the action of the flow stabilizer in separating the fuel mixture having the combined efiect of providing an even flow of oil to thenozzle by the action of the valve 230 as described and also eliminating pulsations from the atomizing air pump 3| by means of the dampening chamber 22l. At the nozzle, it is mixed with the primary air flowing through tube 52 from chamber 5| and is discharged through the orifice 262 as a swirling atomized spray. This spray is ignited by means of the electrodes 58, as described, for combustion with the secondary air supplied by the blower 32 through the tube 250 and the annular passages 255 and 251.

The burner will continue to operate at a constant rate so long as the oil output of the metering pump 30 remains constant, a steady and even flow of fuel to the nozzle being provided by the action of the fiow stabilizer as already described. If this output changes, the change will be compensated for by the action of the differential diaphragm to stabilize the operation of the burner at the new output level. When the burner is shut ofi, by stopping motor 33, the valve 42 closes to shut off the further supply of oil to the metering pump, and any liquid oil remaining in the nozzle and tube 51 will tend to drain back into the flow stabilizer in preparation for the next burning cycle. Also, any oil which may have entered the pressure chamber 45 will similarly drain back into the atomizing pump. When the motor is restarted, substantially the same cycle of operation will take place except that since the fiow stabilizer is already filled with liquid oil, there will be no time delay for filling the compartments 255 and 251, and ignition will take place almost immediately.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. A flow stabilizing device for use in an oil burner of the character described to receive a mixture of oil and air for separation and separate delivery of the air and liquid oil to the burner nozzle, comprising a casing forming a closed chamber, said chamber having an inlet adjacent the top thereof to receive said mixture for separation into air and liquid oil, means for conducting said air from the upper part of said chamber to said nozzle, means forming inner and outer compartments in said chamber having open communication at the top thereof, a flexible diaphragm forming the bottom of said inner compartment and spaced above the bottom of said outer compartment, said inner compartment having greater area in horizontal section than said outer compartment, means forming a passage opening into said inner compartment for conducting oil therefrom to said nozzle, a valve for controlling said opening, and means operatively connecting said valve and said diaphragm to provide for regulating the position of said valve with respect to said passage opening in accordance with the difference in the pressures effective on said diaphragm in said inner and outer compartments.

2. A flow stabilizing device for use in an oil burner of the character described to receive a mixture of oil and air for separation and separate delivery of the air and liquid oil to the burner nozzle, comprising a casing forming a closed chamber, said chamber having an inlet adjacent the top thereof to receive said mixture for separation into air and liquid oil, means for conducting said air from the upper part of said chamber to said nozzle, means forming inner and outer compartments in said chamber having open communication at the top thereof, a flexible diaphragm forming the bottom of said inner compartment and spaced above the bottom of said outer compartment, said inner compartment having greater area in horizontal section than said outer compartment, means forming a passage opening into said inner compartment for conducting oil therefrom to said nozzle, a valve pin for controlling said passage opening, and a button carried by said diaphragm and engaging the lower end of said valve pin to regulate the position of said pin with respect to said opening in accordance with the difference in pressures effective on said diaphragm in said inner and outer compartment, said valve pin and said button having cooperating ground surfaces providing for self alignment and minimum friction between said valve pin and said passage opening.

3. A flow stabilizing device for use in an oil burner of the character described to receive a mixture of oil and air for separation and separate delivery of the air and liquid oil to the burner nozzle, comprising a casing forming a closed chamber, said chamber having an inlet adjacent the top thereof to receive said mixture for separation into air and liquid oil, means for conducting said air from the upper part of said chamber to said nozzle, means forming .inner and outer compartments in said chamber having open communication at the top thereof, a flexible diaphragm forming the bottom of said inner compartment and spaced above the bottom of said outer compartment, said inner compartment having greater area in horizontal section than said outer compartment, means forming a third compartment within said inner compartment and closed at the upper end thereof, said third compartment communicating with said inner compartment at the lower end thereof to receive and entrap air when said inner compartment is filled with oil above the level of the bottom of said third compartment, means within said third compartment forming a passage adapted to receive oil from said inner compartment for delivery to said nozzle, a valve for controlling said opening, and means operatively connecting said valve and said diaphragm to provide for regulating the position of said valve with respect to said opening in accordance with the diiference in the pressures effective on said diaphragm in said inner t and outer compartments, said entrapped air within said third compartment providing a cushion damping out variations in pressure in the fuel supply line to said chamber and promoting a steady and constant flow of liquid fuel to said nozzle.

4. A flow stabilizing device for use in an oil burner of the character described to receive a mixture of oil and air for separation and separate delivery of the air and liquid oil to the burner nozzle, comprising a casing forming a closed chamber, said chamber having an inlet in the upper part thereof to receive said mixture for separation into air and liquid oil, means for conducting said air from the upper part of said chamber to said nozzle, means forming inner and outer compartments in said chamber having open communication at the top thereof, a flexible diaphragm forming the bottom of said inner compartment and spaced above the bottom of said outer compartment, one of said compartments being positioned to receive said oil directly from said inlet to provide for initially filling said inlet with oil and subsequent spilling of said oil into the other said compartment, said other compartment being of greater area in horizontal section than said one compartment, means forming a passage opening into said chamber for conducting oil therefrom to said nozzle, and a valve supported by said diaphragm for controlling said opening to provide for regulating the position of said valve with respect to said opening in accordance with the difference in the pressures effective upon said diaphragm in said compartments.

DELMOND L. GETZ. ROBERT O. HEDGES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,719,501 Denison July 2, 1929 1,724,658 Jennings Aug. 13, 1929 1,799,902 Hoff Apr. 7, 1931 1,817,051 Williams Aug. 4, 1931 1,986,003 Lum Jan. 1, 1935 2,032,291 Lum Feb. 25, 1936 2,090,150 Pontius, Jr. Aug. 17, 1937 2,222,031 Hammer Nov. 19, 1940 2,254,123 Soaper Aug. 26, 1941 2,325,893 Vollmer Aug. 3, 1943 2,397,987 Senninger Apr. 9, 1946 

